Lapping machine



July 3, 1962 E. D. LA FLEUR 3,041,792

LAPPING MACHINE 6 Sheets-Sheet 1 Filed Sept. 14, 1959 mvzwron. EL FHEE'E 11 LA FL-EL/R' ZUMMQ A 'rToE/vE Y E. D. LA F LEUR LAPPING MACHINE July 3, 1962 6 Sheets-Sheet 2 Filed Sept. 14, 1959 NW mwn N Q Q INVENTOR. 55 D. LA FL EUR I E LF'HE Arro R/YE'Y July 3, 1962 Filed Sept. 14, 1959 Fig.3

E. D. LA FLEUR LAPPING MACHINE 6 Sheets-Sheet 3 L34 INVENTOR. E LF'HEBE 17. LAFZEUR' ATTORNEY y 1962 E. D. LA FLEUR 3,041,792

LAPPING MACHINE Filed Sept. 1 1959 6 Sheets-Sheet 4 l 4 II 7 lg- -25? NVENTOR.

. I E1. PHEE'E II. LAl-ZEUR 7 A 7-7-02 NEY July 3, 1962 E. D. LA FLEUR 3,041,792

LAPPING MACHINE Filed Sept. 14, 1959 6 Sheets-Sheet 6 ELF/15121: fi f f fkun 6M0 ATTORNEY United States Patent ()fiiice 3,041,792 Patented July 3, 1962 led 3,041,792 LAPPKNG MACHINE Elphege B. La Fleur, Lancaster, Mass, assignor to Norton Qompany, Worcester, Mass, a corporation of Massaciinsetts Filed Sept. 14-, 1959, Ser. No. 839,717 20 Claims. (til. 51-4154) This invention relates to abrading or lapping machines for lapping or polishing the main bearings and the crank pins of crankshafts and the like and, more particularly, to crankshaft lapping machines adapted for automatic operation and for automatically accommodating the positioning of crankshafts vangularly and axially for the lapping operation, engaging and adjusting the lapping or polishing abrading medium, etc., substantially without the necessity for continued manual control or operation.

In the manufacture of crankshafts for internal combustion engines, the several axially aligned main bearings of the crankshaft and the several eccentrically disposed crank pins thereof are polished or lapped, after having been preliminarily ground to size, to provide thereon the final smooth or polished finish desired. In the interests of speeding production and minimizing the length of time each individual crankshaft must rest in the lapping operation, it may be desired to perform the lapping or polishing of all main bearings and crank pins on a crankshaft simultaneously as by having a plurality of lapping jaws each of which holds a strip of abrasive tape around a main hearing or a crank pin on the crankshaft while the crankshaft is rapidly rotated to perform the polishing against the abrasive strip, generally along the lines disclosed in U.S. Patent No. 2,166,009.

As will be understood, the various mechanical motions involved in such an operation may be quite complex in that, while the abrasive strips for the main bearings are contacting axially aligned rotating portions, other abrasive elements for the crank pins must undergo a somewhat planetary motion as the eccentric crank pins are being rotated about the main axis of the shaft and furthermore, in order to maintain a uniform lapping operation without surface marks, it may be desired to reciprocate the rotating shaft axially with respect to the brading or lapping elements, and it also may be desired to present new and unused surfaces of the abrading medium to each new crankshaft to be polished.

Also, the positioning of the several elements of the lapping machine for accomplishing the desired lapping operation and the desired movements required thereby may be such that difiiculty is experienced if it is attempted to load a crankshaft into lapping position in the machine,

adjust its position axially and angularly with respect to the abrading elements for the lapping operation, and unload a lapped or polished shaft from the machine automatically, instead of manually, and a longer than optimum overall time cycle per crankshaft may be required, with less than optimum economies of operation, if each crankshaft must be manually loaded into the machine while at rest, adjusted into position, and then the action of the machine started and manually controlled, in addition to the disadvantages or loss of economies arising from the necessity of having an operator for controlling each lapping operation on the individual crankshat'ts. Yet, as noted, the positioning of the several elements involved may be such as will present difiiculty in an attempt to load and adjust the Work pieces or crankshafts automatically from automatic conveyors and the like.

According to this invention, however, crank pin lapping apparatus of the character described is provided for simultaneously lapping main bearings and crank pins of a crankshaft by the rotation thereof against abrasive tapes or strips held around the respective surfaces to be polished by lapping jaws, and also with the provision of loading and handling means for receiving a crankshaft automatically from automatic conveyor means, positioning the crankshaft with respect to the lapping or abrading elements axially and angularly, automatically starting and timing a lapping or polishing cycle, withdrawing the finished shaft on the completion of the cycle to an unloading position for discharge to automatic conveying means, and including automatic electrical and hydraulic circuits for repeating the cycle, re-setting timing and adjusting means, and means for presenting new abrading surfaces for subsequent crankshafts to be ground, all automatically and substantially without the necessity for manual control or supervision by an operator.

One object of this invention is to provide, for automatic operation in association with feeding and discharge conveyors, a crankshaft lapping machine of the character described for the simultaneous lapping or polishing of main bearings and eccentric crank pins of a crankshaft and including provision for receiving a crankshaft, positioning it axially and angularly with respect to the abrading elements, locking it into position, automatically rotating it for a predetermined time cycle, and then delivering the finished shaft back to the loading position for discharge into an automatic conveyor while re-setting the machine and the abrading elements for receiving a subsequent crankshaft automatically.

Another object of this invention is to provide, in a crankshaft lapping machine of the character described, means for receiving a crankshaft to be ground, means for positioning the crankshaft axially and angularly with respect to abrasive lapping elements and for clamping or locking the crankshaft in rotating drive means, and means for presenting the rotating crankshaft properly positioned to lapping and polishing elements automatically, and including means for adjusting and positioning and re-setting the lapping or abrading elements after each lapping cycle to receive a subsequent crankshaft automatically loaded thereinto.

A still further object of this invention is to provide in an automatic lapping machine of the character described, the various mechanical and electrical and hydraulic controls and circuits and interlocks for providing the desired sequence of operations automatically, for preventing premature starting of any particular operation, for adjusting and maintaining the axial and angular positioning of the several parts with respect to the surfaces to be lapped, for automatically timing each lapping cycle, and for re-setting the machine between cycles to prepare for a repetition of cycle with a subsequent workpiece to be lapped or polished.

Other objects and advantages of this invention will be apparent from the following description, the accompanying drawings, and the appended claims.

In the drawings:

FIG. 1 is a top plan view of a crankshaft lapping machine embodying and for practising this invention and showing a crankshaft in loading position with the machine between cycles;

FIG. 2 is a view along the line 22 of FIG. 1, with some parts bro-ken away;

FIG. 3 is a view on a somewhat enlarged scale in sub stantially vertical section of a portion of headstock and drive components shown in the lower left corner of FIG. 1 but with the parts moved to a different angular position;

FIG. 4 is a view in substantially vertical section on an enlarged scale similar to FIG. 3 of the corresponding footstock portions and elements shown in the lower right hand corner of FIG. 1 but with the parts in the same angular positioning as in FIG. 3;

FIG. 5 is a side elevation of the footstock arrangement of FIG. 4, taken from the right hand side thereof, and showing the parts in two angular positions of the assembly;

FIG. 6 is a detailed view of the initial support for the end of a crankshaft adjacent the footstock of FIGS. 4 and 5;

FIG. 7 is a partial side elevation from the right of the initial supporting block for the end of a crankshaft 'adjacent the headstock assembly of FIG. 3, with the parts shown in a different position than the same parts are shown in FIG. 2;

FIG. 8 is a partial side elevation from the left side of FIG. 1 showing a portion of the drive and control elements illustrated along the left side of FIG. 1;

FIG. 9 is a partial horizontal section with parts broken away showing a detail of the axial reciprocating mechanism of FIG. 3;

FIG. 10 is a partial vertical section through one of the crank pin lapping arms and taken substantially along the line lit-10 of FIG. 1;

FIG. 11 is a fragmentary top plan view of the mechanism of FIG. 10 and taken along the line ill-11 thereof;

FIG. 12 is av detail view with parts broken away showing an overrunning clutch for use in the automatic abrasive tape feeding mechanism of FIG. 2;

FIG. 13 is a detail view on an enlarged scale with parts broken away of part of the control and sensing mechanism for adjusting the final angular positioning of a crankshaft and the lapping arms upon the completion of a lapping cycle; and

FIG. 14 is a diagrammatic view illustrating various of the electrical, mechanical, and hydraulic control and adjusting and actuating mechanisms in a machine embodying and for practising this invention.

Referring to the drawings, in which like reference characters refer to like parts throughout the several views thereof, an illustrative embodiment of an automatic crankshaft lapping machine according to this invention is shown, generally, in FIGS. 1 and 2 as having a base having an extended top portion 21 and a parallelly disposed depressed top portion 22, with two upstanding side supports 23 and 24 for supporting the lapping or polishing elements and associated mechanism.

A headstock assembly 39, including rotating drive means explained below, and a live-center footstock assembly are provided for clamping a crankshaft to be polished therebetween, with means described below in headstock 3% to engage and rotate crankshaft 4%? about the main axis thereof and with the opposite end of crankshaft 40 being supported by the freely rotating pointed center of footstock 35 engaging a central depression in the crankshaft. Headstock assembly 30 and footstock assembly 35 are mounted on rocking frames and 46 respectively, which are, in turn, fixedly mounted adjacent opposite ends of rocking shaft 50 extending substantially across the machine and mounted for rotation with respect thereto as by hearing brackets 51 and 52 afiixed to depressed top portion 22 of base 24), whereby, if shaft 50 is rotated in brackets 51 and 52, frame members 45 and 46 will rotate therewith to move headstock assembly 30 and footstock assembly 35 together (along with a crankshaft 40 therebetween) from an outward loading and unloading position to an inward lapping position as indicated, for example, by comparison of the showings of FIGS. 2 or 5 with FIG. 10.

'A plurality of lapping arms 69-439 are provided (mounted as described below between side walls 23 and 24 above top 21), including one for each of the main bearings and crank pins of crankshaft 49 to be polished. In this illustration, lapping arms 62, 64, 66, and 63 are crank pin lapping aims, whereas the remainder are main bearing lapping arms. As is well understood in this art, each of the lapping arms 6(i69 is provided, at the operating end thereof, with a pair of pivoted lapping jaws 7079, dimensioned as to width and curvature to accommodate the main bearings and/or crank pins to be lapped, and each includes means for leading along the lapping arms and. through the lapping jaws a strip or tape of abrasive material to perform the lapping or polishing function in known manner, said strips or tapes of abrasive being indicated by the references 60 6 respectively. (It should here be noted that, in the interests of clarity in FIG. 1, only the respective abrasive strips 6il,,6 have been referenced, it being understood that the corresponding lapping arms underlie the respective strips, with lapping jaws 7ti--79, respectively, appearing at the lower end of strips Mt -6% in FIG. 1.)

With the foregoing preliminary explanation in mind, it may be helpful to consider now some aspects of the overall functioning and mode of operation of a machine embodying and for practising this invention before continuing with a more detailed disclosure of the particular structures and elements involved.

Thus, with headstock assembly 30 and tailstock assembly 35 (as carried by rocking frames 45 and 46) rotated to a loading position (i.e., leaning to the left in the drawings, as indicated in FIG. 2 and by the full line showing of FIG. 5 and as shown from the top in FIG. 1) a crankshaft 4G is loaded (as by dropping from above) between headstock 30 and footstock 35 and clamped therebetween to be rotated along the main axis of the crankshaft by the drive mechanism in headstock 30. At this time, lapping arms 60-69 are arranged with the respective lapping jaws 70-79 open and variously positioned, as indicated in FIG. 2, according to the particular vertical, horizontal, and axial position of the particular main bearings or crank pins which each particular lapping arm is about to engage.

Headstock 30 and footstock 35, with crankshaft 40 therebetween, are then rotated from the outward or left hand loading position to the inward or right hand lapping position, by rotation of rocking frames 45 and 46 on shaft 50, inwardly toward lapping jaws 7079 (i.e., toward the right in the drawings as indicated by FIG. 10 and the dot-dash line showing of FIG. 5) whereby each main bearing and crank pin to be lapped is received within a respective one of lapping jaws 7( --79, all of which then close around the bearings and crank pins from the open position indicated in FIG. 2 to the closed or lapping position indicated in FIG. 10. Rotation of the crankshaft is then commenced by the drive mechanism through headstock 30, and lapping or polishing thereof ensues by rotation of the main bearings and crank pins against abrasive strips or tapes wi -6% as held wrapped about the rotating bearings or pins by the respective lapping jaws 7079 on the respective lapping arms 60-69. Since crankshaft 40 is being rotated about the main axis thereof, those .of the lapping arms (e.g., 69, 61, 6'3, 65, 67 and 69) which engage main bearings or axially aligned portions of crankshaft 40 remain substantially stationary during the lapping operation, whereas those of the lapping arms (e.g., '62, 64, 66, and 68) which engage eccentric crank pin portions of the shaft, must execute a somewhat planetary or pivoting and reciprocating motion such as the motion incurred by a piston connecting rod attached to one of the crank pins when the crankshaft is in use in an engine.

Upon completion of the lapping or polishing operation or cycle, rotation of crankshaft 40 is stopped (preferably at a particular angular positioning thereof whereby the respective lapping arms 6tl-6 are properly positioned for lapping jaws 70-79 thereof to engage and receive a subsequent crankshaft oriented to the same angular positioning), jaws 70-79 are opened, and crankshaft 40 withdrawn therefrom by rotation of headstock assembly 30 and footstock assembly 35 on frames 45 and 46 back to the starting or left hand position shown in the drawings for removal or unloading of crankshaft 40 from between headstock assembly 30 and footstock assembly and for replacement therebetween of a subsequent crankshaft to be polished for a repetition of the lapping cycle.

Although the structures and the controls, etc, for effectuating, automatically, the foregoing operations are described in more detail below, the foregoing steps represent, generally, the sequence and mode of operation desired or preferred for a crankshaft lapping machine embodying and for practising this invention. It should also be noted that the foregoing arrangement is susceptible to automatic loading and unloading of the crankshafts into the machine as from automatic conveying apparatus, particularly because, for example, whereas direct vertical loading or unloading of the crankshafts may be precluded by the extended positions of some .of the lapping arms 6tl 69 when the headstock 3i and footstock 35 are in the lapping position indicated in FIG. 10, no interfering elements of the machine extend above crankshaft when the headstock and footstock assemblies 3d and 35 are swung to the outward loading position indicated in FIGS. 1 and 2, thus permitting substantially free access to the machine from above for loading a new crankshaft or picking up a finished crankshaft with an overhead conveyor (indicated diagrammatically at Se in FIG. 2, such as, for example, automatic crankshaft transfer means along the lines disclosed in 11.8. Patent No. 2,780,985).

Referring now to headstock assembly 3t} and the associate drive means for the illustrated machine, it will be noted that the principal motive power is provided by main drive motor 98* operating through motor shaft 91 on which is mounted a pulley 92 for transmitting power through ribbed belt 93 to pulley 94- on a jack-shaft 95. Jack-shaft 95, on which pulley 54 rotates freely on bearings indicated at 96, is mounted concentrically with shaft 5% in brackets 51 and 52 on top 22 of base 29, and pulley 94 includes a cogged integral hub 97 thereon for driving engagement with a ribbed belt 95 to drive pulley 99 on drive shaft 10% of headstock assembly 30, with pulley 99 keyed to shaft 160, as at 1411, for positive driving engagement therewith. As will be seen, the foregoing arrangement maintains constant spacing on the various belted pairs of pulleys regardless of the particular angular position of headstock 3t} and the axis of drive shaft 100 as headstock assembly 3t} is rotated from an outward loading position to an inward lapping position about the axis of shaft 54 As indicated more particularly in FIG. 3, shaft 100 is journaled for rotation in bearings 102 and 193 mounted within housing 110 of headstock assembly 36, and carries adjacent the right-hand end thereof a sealing ring 111 and rotating driving head assembly 112 for clamping and driving engagement with a flange 113 at one end of crankshaft 4%. Member 112 also includes a projecting eccentrically mounted pin 114 with a tapered end portion for engagement with a corresponding bore 115 in flange 1'13 of crankshaft 4i} to provide positive rotational driving engagement therewith as the crankshaft is urged against member 112 by the action of fcotstock assembly 35 described below.

Housing 110 of headstock assembly 30 is mounted upon frame by means of four brackets 126 depending from the bottom 121 of housing 114), which brackets engage two rods 125 affixed in upstanding ears 126 at the top of frame 45. Within brackets 12%, and actually contacting rods 125, are arranged a plurality of ball bearings 127, this whole arrangement providing for axial sliding or oscillation of headstock housing 110 with respect to frame 45 so that headstock assembly 30 and footstock assembly 35 (and crankshaft 46 held therebetween) will all be oscillated or reciprocated axially to a definite but limited extent during the lapping operation to provide for uniform polishing on the bearings and crank pins by abrasive tapes 641;, etc., and to avoid the possibility of grooving or producing a uniform circumferential abrasive pattern on the surfaces being polished. Such oscillation or reciprocal movement of housing of eadstock assembly 30 is provided, preferably, by a reciprocating drive mechanism mounted within frame 45, as indicated in FIGS. 3 and 9. Thus, a cogged pulley 13b is keyed to shaft 108 and connected by a ribbed belt 131 to pulley 132 which is fastened to shaft 133 journaled for rotation in suitable bearings, etc., in a housing 134 mounted within framedS. A worm 135 is: rotated by shaft 133 and, in turn, drives a worm gear 136 afiixed to a vertical shaft 137, also journaled in housing 134. The upper end of vertical shaft 137 engages an eccentric 138 connected at 139 to a link 140, which is connected as by pivotal connection 141 to the bottom plate 121 of housing 110, thus providing, in known manner, positive axial oscillation of housing 110 to the limited degree desired and as deter-mined by the foregoing drive and linkage. A tie rod is connected at 151 to a depending arm 152 affixed to housing 110 for imparting a corresponding oscillating or reciprocating movement to footstock assembly 35 as noted below.

Also mounted on headstock assembly 3b is limit switch assembly 2L5, described below in connection with the control circuits of the machine, for sensing and determining the particular angular positioning in which it is desired to stop the rotation of crankshaft 40 at the end of the lapping operation in order that the particular angular positioning thereof will be such as to orient the various lapping arms 60-69 properly to receive the next crankshaft to be lapped or polished. The mechanical arrangement of assembly 2L8 is indicated in FIGS. 3 and 13 as including a cogged pulley (preferably integral with pulley 130) fixed for rotation with shaft 100. A ribbed timing belt 161 drives pulley 162 on the 2L5 assembly, and pulley 162 drives rotor 165, journaled in housing 166 of the 2L5 assembly. As noted more particularly in FIG. 13, the enlarged enclosed portion 167 of housing 166 includes a limit switch having contacts 170 and 171 positioned adjacent the right hand end of rotor and spring-biased to closed position. Rotor 165 has a flattened portion 172 thereon, and contact 171 carries a rubbing block 175 contacting rotor 165 in such manner as to maintain contacts and 171 open except when rubbing block engages fiat 172.

Referring now to FIGS. 4 and 5, the arrangement of footstock assembly 35 is shown in somewhat more detail,

as including a cylindrical housing having a bottom plate 181 with depending brackets 18 2 for mounting on parallel axial rods 183 afiixed to upstanding ears 184 of frame 46, in generally the same Way as the corresponding arrangement just described for mounting housing 110 of headstock assembly 30 on frame 45. Brackets 182 include roller bearings 185 providing for axial oscillation or reciprocation of footstock housing 180, and tie rod 154), pivotally connected at with depending arm 191 on housing 180 produces such limited oscillation or reciprocation of footstock housing 180 along with headstock housing 110 as driven by reciprocating drive means illustrated in FIGS. 3 and 9 to reciprocate crankshaft 40 during the lapping or polishing thereof.

Mounted within cylindrical housing 180 for axially slideable movement with respect thereto is cylindrical member 195 carrying at the left end thereof freely rotating spindle arrangement r196 carrying pointed footstock center pin 2%. Preferably, since cylinder 195 is freely axially slideable in housing 180, a flexible bellows arrangement 291 #is provided therebetween to protect and keep enclosed the sliding surfaces of 195 in housing 189.

As will be understood from the foregoing, when memher 195, and, of course, centerpin 200, are axially retracted to the right in FIG. 4 (to the dot-dash position shown or to the position indicated at FIG. 1), a crankshaft it) may be freely placed between headstock assembly 3t and footstock assembly 35. When cylindrical member 195 is advanced to the left to the full line position shown in FIG. 4, the pointed center pin 200 engages a corresponding depression in one end of crank shaft 4% and clamps it axially between headstock assembly 30 and footstock assembly 35, and the freely rotating mounting of spindle 1% in member 155 provides for the anti-friction rotation of crankshaft 4ft as clamped axially in position, in known manner.

In the particular arrangement shown, it is desired that this axial movement of member 195 occur during or upon rotation of the headstock and footstock assemblies from the loading or open position into the operating position of the machinei.e., during movement of headstock and footstock 30 and 35 on frames 45 and 46 upon rotation of shaft 50 from the full line position shown in FIG. to the dot-dash line position shown therein, corresponding to the situation in FIG. 4. To this end an inclined cam surface 205 is provided on an upstanding bracket 2th; fixedly mounted with respect to table top 22 as, for example, on fixed bracket 52. An arm 210 is aflixed to the end of member 195 opposite to center pin 2% and carries a cam follower 211 for engaging cam surface 205. Thus, as footstock assembly 35 is rotated about the axis of shaft 561 from the position shown in FIG. 4 toward the viewer of the drawing (i.e., from the dot-dash position of FIG. 5 toward the full line position thereof), cam follower 211, engaging and riding along inclined cam surface 295, will draw member 195 to the right in the drawing and thus retract center pin b away from its engagement with crankshaft 40. Upon movement in the opposite direction about shaft 59 cam follower 211 will displace member 195 to the left in FIG. 4, as cam follower 211 travels along cam surface 215. In order to preclude damage to the machine or to a crankshaft during loading, due, for example, to the insertion of a relatively long crankshaft, cam surface 215 is pivotally mounted at 216 to fixed upright 2116 for engaging the right side of cam follower 21 -1 and is continuously yieldably urged to the left into engagement with fixed stop 214 under the action of spring 217 acting through bolt 218 against an upstanding flange 2 19.

In order to provide a positive locking, rather than a resilient clamping, of center pin 200 to the left in FIG. 4 when engaged with crankshaft 40 during a lapping operation (and where, as in FIG. 4 cam follower 211 is beyond contact with either cam surfaces 25 or 215), a pin 220 is provided in sliding member 195 having a head portion engaging a transverse cam follower arm 221 pivoted at 222 on housing 180. Arm 221 has a cam follower roller 223 riding on a cam surface 225 mounted on fixed upright 206, and arm 221 is biased downwardly by a spring arrangement indicated at 226. Such an arrangement, then, as particularly noted in FIG. 5, and with proper configuration of cam surface 225, provides for raising cam follower arm 221 from the position shown in FIG. 4 (or the dot-dash position of FIG. 5) out of engagement with pin 220 before cam follower 211 contacts cam surface 205, thereby causing cam follower 21 1 to slide member 195 to the right as it engages cam surface 255. In the reverse direction of movement, cam surface 205 is configured so that, as the cam follower 211 moves out of engagement with cam surface 215, arm 22 1 starts dropping into the position shown in FIG. 4 to engage pin 221D and positively lock member 195 and center pin 2th} in the left hand or operating position shown in FIG. 4. As will also be understood, arrangement of the locking surface 227 of arm 221 in a sloping configuration provides means to accommodate crankshafts of varying lengths within the limits normally encountered in mass production manutfacturing operations.

In the illustrated embodiment, as noted above, positive driving of crankshaft 40 for rotation in the operating position as clamped between headstock assembly and footstock assembly is achieved by engagement of pin 1 14 on the headstock assembly 30 with a bore or depression 115 in a flange 113 on crankshaft 40. Automatic axial disengagement of crankshaft from pin 114 as,

for example, upon completion of a lapping cycle, is prefably achieved also by an arrangement associated with the foregoing camming arrangements. Thus, arm 210 carries at one end thereof a clamping flange 230 for engaging an elongated rod 231 slideably supported in a bracket 232 mounted on housing 180. Rod 231 extends, particularly as indicated in FIG. 1, for a length sufficient for an enlarged knob 235 at one end thereof to engage crankshaft 41 by overlapping one of the eccentric counterweight portions thereof, so that, as arm 210 is forced to the right in FIGS. 1 and 4 by the camming action of cam follower 211 and cam surface 255, rod 231 will be similarly urged to the right in the drawings so that knob 235 at the end thereof, engaging a portion of crankshaft 40', will pull crankshaft 4t) sufiiciently to the right in the drawings to disengage pin 114 on headstock assembly 30 from the depression 115 in flange 113 of crankshaft 40 thus releasing crankshaft 40 for direct vertical lifting out of the machine.

The particular mechanism for moving headstock assembly 3t and footstock assembly 35 from the open or loading and unloading outward position (indicated in FIGS. 1 and 2 and the full line position of FIG. 5) into the operating or lapping position (indicated by the dotdash showing of FIGS. 5 and 10) is, perhaps, most readily apparent from FIG. 2. In the illustrated embodiment, the motive power for such movement and the operations associated therewith is provided by a hydraulic cylinder-piston-motor and a mechanical linkage, the operation of which is controlled by and associated with the various electrical and hydraulic control arrangements discussed below.

Thus, as indicated in FIG. 2, hydraulic cylinder 250 is provided, having operating therein piston 251, with cylinder 25% including provisions, in known manner and vides rotation of shaft 59, (on which are mounted headstock assembly 30' and tailstock assembly 35 through their respective mounting frames 45 and 46) through piston rod 252, link 253, and arm 254 clamped to shaft 50. Thus, movement of piston 251 in cylinder 250, under the action of hydraulic fluid pumped into cylinder 250, from the left hand position shown in FIG. 2 to the extreme right hand extent of the throw of piston 251 in cylinder 250, provides for movement of arm 254 from the position shown in FIG. 2 (with the upper end thereof at approximately a ten oclock position) to the right in FIG. 2 where the upper end of arm 254 is at approximately a two oclock position, with, of course, concomitant rotation of shaft 50.

Since headstock assembly 30 and footstock assembly 35 are mounted, respectively, on rocking frames 45 and 46 affixed to shaft 50 for rotation therewith, such movement of piston 251 to the right in FIG. 2 produces a corresponding rotating movement of headstock assembly 30 and footstock assembly 35 from the outward or loading position indicated in FIG. 2 and the full line showing of FIG. 5 to the operating or lapping position indicated by the dot-dash line showing of FIG. 5 or 10, with the extent of such inward movement to the right in FIG. 2 being adjustably limited by abutments 256 and 257 on, respectively, rocking frames 45 and 46 contacting adjustable stops 258 and 259 mounted on supporting means fixedly secured to top 21 of base 20 within the machine.

As will be recalled from the foregoing, a crankshaft 40 is placed between headstock assembly 30 and footstock assembly 35, while the footstock center pin 2% is retracted to open position, and then the crankshaft is clamped between headstock and footstock as center pin 200 is moved into clamping position during swinging of the assemblies to the right in FIG. 2. Accordingly, particularly for automatic operation, means are provided for initially or temporarily supporting crankshaft 4i) between headstock assembly 3t) and footstock assembly 35 until suchtimes as, during the swinging movement of these assemblies, the camming action discussed in connection with FIG. 4 has an opportunity to move footstock center 200 into clamping engagement to hold crankshaft 4t clamped and engaged for rotation between headstock assembly 30 and footstook assembly 35. In the illustrated embodiment, such means are indicated in FIGS. 2, 4, 6, and 7.

Thus, with the machine at rest and the headstock assembly 30 and the footstock assembly 35 in the loading or open position indicated in FIG. 2, a crankshaft 40 is deposited (either manually or from automatic conveyors as indicated at fill) between headstock 30 and footstock 35 to rest, temporarily, on a V-block 265 adjacent the headstock assembly 30 and another V-block 266 adjacent and, preferably mounted on, housing 180 of footstock assembly 35. In the illustrated embodiment, V- block 265 temporarily and initially supports crankshaft 40 at a main bearing portion thereof which it is desired to polish or lap, so that arrangement is made for moving V-block 265 out of the way of lapping jaws 71 during the lapping operation, whereas, by contrast, V-block 266 is positioned to support the opposite end of crankshaft 40 in an area thereof in which no lapping or polishing is desired and where the V-block will not interfere with lapping operations.

Regarding the latter, nevertheless, provision is made to avoid interference between V-block 266 and the rotation of crankshaft 40 as clamped in the machine. For example, as illustrated in FIG. 6, the V of V-block 60 is specifically positioned with respect to the center point of center pin 200 so that, as indicated by the dot-dash circle in FIG. 6, the axial center of crankshaft 40' as supported in V-block 266, is a fraction of an inch below the axial center line of center pin 200. Since center pin 206 is tapered or pointed for interfitting engagement into a substantially correspondingly tapered indentation in the end of crankshaft 40, insertion of tapered center pin 2% into the indentation in crankshaft 40 will raise that end of crankshaft 40 by an extent sufficient to avoid contact of the crankshaft with V-block 266 during rotation thereof.

Regarding V-block 265 supporting the other end of crankshaft 49 adjacent the main bearing area to be lapped or polished by lapping jaws 71 on lapping arm 61, an arrangement for removing V-block 265 from a position interfering with the lapping operation after its temporary supporting function is fulfilled is illustrated in PEG. 7 (and by comparison with FIG. 2). Thus, prior to clamping crankshaft 40 between headstock assembly 30 and footstock assembly 35 before a lapping operation (or subsequent to the release of crankshaft 40 from clamping engagement after a lapping operation), one main bearing of the crankshaft is supported on V-block 265 as mounted on a cross arm 27%), having one end pivoted at 271 to one arm of a bellcrank 272, the opposite end of the other arm of bellcrank 272 being clamped around shaft 50 for rotation therewith. The opposite end of cross arm 27% carries a cam follower roller 273 supported, as

indicated in FIG. 2, on an upright cam surface 274 fixedly mounted on a bracket on top portion 22 of base 20. As the entire headstock assembly 30 and footstock assembly 35 is moved to the right in FIG. 2 upon turning of shaft 50 under the action of cylinder-piston 259-451, bellcrank 272 is also turned by shaft 50 and moves cam follower 273 along the top of stationary cam surface 274. The extent and curvature of cam surface 274 are correlated with the length of cross arm 270, etc., so that,

as soon as crank shaft 40 is at least initially clamped between headstock assembly 30 and footstock assembly 35 by the advancement of center pin 200 toward the left in the drawings, cam follower 273 runs off the righthand side of cam surface 274 (into the position indicated in FIG. 7), thus moving V-block 265 downwardly and out of engagement with crankshaft 40, as well as out of the way of lapping jaws 71 so that the supported surface of crankshaft 40 can be freely engaged thereby. By the same token, upon unloading movement of the headstock 3i) and footstock 35 to the left in FIG. 2, a corresponding reverse movement is incurred by cam follower 273 and cross arm 270, whereby V-block 265 is brought back into an upright crankshaft engaging position, as indicated in FIG. 2, to accept or receive crankshaft 40 as it is unclamped and disengaged from between headstock assembly 30 and footstock assembly 35, by the camming action discussed in connection with FIG. 4, in order that the crankshaft 4%) will once again be resting freely on V-blocks 265 and 266 to be picked up, either manually or automatically, for removal from the machine and replacement with a subsequent crankshaft to be lapped.

Referring now, particularly, to FIGS. 2, l0, and 11, the particular arrangement of the various lapping arms 60- 69 and the appertaining lapping jaws 7079 and abrasive strips or tapes 6il 69 may be considered. Thus, as noted above, the various lapping arms and lapping jaws, etc., may be generally, considered similar to each other, and for purposes of illustration, may all be illustrated by the single lapping arm (in this case, 62) illustrated in vertical section in FIG. 10, as comprising an arm member 280 having mounted at the rear end thereof a cylinder-piston-motor comprising hydraulic cylinder 281 in which operates piston 282, with provision such as hydraulic fluid coinduits 283 and 284 for admitting hydraulic fluid into cylinder 281 on either side of piston 282 for the positive movement thereof selectively in either direction longitudinally of cylinder 281. Piston 282 operates piston rod 285, connecting with longitudinal link 286 within portion 280 of the lapping arm for axial sliding movement therethrough, and the opposite end of link 286 is pivotally connected with two links 287 extending vertically through portion 280. Each of links 287 is pivotally connected at its outer end with one end of a bell crank 288, the center portion of each of which is pivoted at 28% to a stationary member 290, and has the opposite end thereof aflixed to mating cooperative members 291 of the lapping jaws (in this case, 72).

As will be apparent from the foregoing, a toggle action is achieved whereby, upon movement of piston 282 from the position shown in FIG. 10 toward the right end of cylinder 281 under the action of hydraulic fluid injected thereinto, piston rod 285 and link 286 will be drawn to the right in FIG. 10 within member 280 of lapping arm 62, thereby breaking the linkage 287 into the dot-dash line position indicated in FIG. 10, and moving closer together the pivoted ends of bell crank 288, so that members 291 of the lapping jaws will be opened into the open position indicated in FIG. 10 by a dot-dash line showing and/or similar to the open positions of lapping jaws indicated in FIG. 2. In this open position of FIG. 2 (or the dot-dash position of FIG. 10), lapping jaws 70- 79 are positioned to receive one of the main bearings or crank pins to be lapped, and, after such hearing or crank pin is in position in the lapping jaws (as, for example, by the movement of crankshaft ill clamped between headstock assembly 30 and footstock assembly 35 from the outer loading position of FIG. 2 into the position indicated for frame 45 by the dot-dash line of FIG. 10), admission of hydraulic fluid into cylinder 28 1 on the right hand side of piston 282 in FIG. 10 forces piston 282 to the position shown and, through the linkage 28529 l, closes the jaw members 291 of the lapping jaws around the surface of crankshaft 4-0 to be polished or lapped.

As previously noted, those of the lapping arms situated to engage axially aligned bearing surfaces of crankshaft 40 (e.g., 6t), 61, 63, 65, 67, and 69) need participate in no particular vertical or horizontal movement, whereas those of the lapping arms positioned to engage eccentric crank pins of crankshaft 40 (e.g., 62, illustrated in FIG. 10, 64, 66, and 68, illustrated in FIG. 2) are mounted to partake of the same sort of movement as a piston connecting rod affixed in use to the particular crank pin of crankshaft 40 being lapped or polished. In any case, all of the lapping arms 60--69 are generally supported in the illustrated machine (FIGS. 10 and 11) between a series of vertical upright plates or supports 300 depending from transverse rods 301 supported between upright side members 23 and 24 (it being noted, particularly, that the details of such support mechanisms are omitted from FIG. 1 for clarity, but are indicated in FIGS. 2, 10, and 11). In addition to vertical support 300, the various lapping arms 6(l69 are similarly and simultaneously supported by a transverse rod 305 running across the machine between vertical side :members 23 and 24, and passing through a suitable hole or slot in the portion 280 of the various lapping arm's 6069, and spaced a substantial distance rearwardly from vertical supports 300.

As will be understood, supporting one end of lapping arms 6tl69 on transverse rod 395 provides, essentially, a pivotal support. Since lapping arms 69, 61, 63, 65, 67, and 69 engage axially aligned portions of crankshaft 46, substantially no vertical or pivoting motion thereof is required during the lapping operation, and satisfactory support is achieved by having transverse rod 305 merely pass through a hole in these lapping arms and having the other end thereof supported by stationary stops or pins 31%} between upright plates on either of the designated lapping arms. Since, on the other hand, lapping arms 62, 64, 66, and 68 undergo a reciprocating or oscillating and pivoting motion during the lapping operations as engaged with eccentric crank pins of the crankshaft 4-0 (as indicated by the several dot-dash positions shown in FIG. 10), satisfactory support of these lapping arms is achieved by providing a slot 33.1 therein for accommodating transverse rod 3&5 so that the designated lapping arms may pivot and oscillate axially with respect to transverse rod 395, the opposite ends of the designated crank pin lapping arms being supported during the lapping operation by the eccentric crank pin portions of crankshaft engaged within lapping jaws 72, 74-, 76, and 73, respectively. Upon completion of the lapping or polishing operation and release of lapping jaws '72, etc., from the respective crank pins of crankshaft 4%, however, some provision is desired for supporting the left end (in FIG. 10) of the crank pin lapping arms and, particularly, to hold the jaws 72, etc., thereof vertically in a proper position to receive a subsequent crankshaft to be lapped.

A satisfactory arrangement for accomplishing the foregoing is also illustrated in FIGS. 10 and 11 as comprising a shaft 324) rotatably mounted transversely of the machine and having mounted thereon for rotation therewith arms 321 each of which carries an adjustable stop 322. As will be noted from comparison of the full line and dot-dash line showings of FIG. 10 as well as by the showing of FIG. 2, arms 321 with stops 322 are retractable from a substantially vertical to a substantially horizontal position and, in the former position, adjustably support the various ones of lapping arms 62, 64, 66, and 68 in a stationary position (FIG. 2) to receive the respective crank pins of the crankshaft 40 to be ground, and then are retracted into the full line position of FIG. upon clockwise rotation of shaft 320, to permit free vertical movement, as may be required, of the respective lapping arms, so that the vertically movable lapping arms can be temporarily held in the proper vertical position between lapping cycles to receive the appropriate portions of the crankshaft, and then arms 32 1 and stop 322 thereon can be retracted out of stopping or supporting arms.

A satisfactory arrangement for the intermittent or timed rotation of shaft 329 to move arms 321 and stops 322 thereon into and out of supporting relation with the designated lapping arms is indicated in FIG. 2 (with the control and timing details for the actuation thereof being indicated below in connection with the discussion of FIG. 14). Thus, a hydraulic cylinder-and-piston motor 325 is provided with means for injecting and withdrawing hydraulic fluid into the cylinder selectively on either side of a piston moving axially therein, for urging the piston selectively either to the left or to the right end of the cylinder 325 in FIG. 2. The piston in the arrangement 325 actuates piston rod 326, which, in turn, through a linkage with one arm of bell crank 327, rotates shaft 320 and all the various arms 321 afixed thereto, it being understood that the different vertical positionings of the left end of the various designated lapping arms are achieved by different angular placement of the several arms 321 around the axis of shaft 326 and the separate adjustments of adjustable stops 322 thereon.

The actual abrading or polishing medium (in the form of abrasive tapes or strips 6Ga69a) is supplied from rolls of such material indicated at 340 as being freely mounted on a rotating core 341 in tape housing 342 at the rear of the machine and extending transversely thereacross, and are simultaneously fed from rolls 340 (particularly as indicated in FIGS. 2 and 10) forwardly through the machine (preferably passing under a series of guides comprising spacers 345 mounted on the lower pair of rods 391 through vertical strips 3%), around the ends and over the inside surfaces of lapping jaws 7tl-79 (compare FIGS. 2 and 10 for the tape feed in the open and closed position of the lapping jaws previously described), and up over a rod 346 running transversely of the machine between side uprights 23 and 24 and adjacent the upper portion thereof, and, thence, between knurled feeding rolls 350 and 351, also extending transversely across the machine and engaging therebetween all the tapes 6tta69a for the intermittent feeding thereof through the machine as may be required to present a new and unused abrasive surface adjacent lapping jaws --79 for subsequent crankshafts to be polished, with the used tape passing from the knurled feeding rolls 3% and 351 into a waste tape receptacle indicated at 353.

Knurled rollers 350 and 351, by gripping the several abrasive tapes 6t)a69a therebetween (as by having knurled roller 351i mounted on an arm 352 spring biased downward by the spring arrangement 354 to mate with knurled roller 350), assure a positive feeding of abrasive tapes through the machine. To accomplish this intermittent feeding automatically (preferably during timed out portions of the machine operation between lapping cycles), an arrangement is provided, as indicated in FIG. 2, comprising a cylinder-and-piston motor 360 in which the piston is selectively actuated for up and down motion within the cylinder and activates piston rod 361 connected by an adjustable delayed linkage 362 with an arm 365 of an internally spring-biased overrunning clutch arrangement (particularly indicated in FIG. 12) connected to knurled roller 350. Thus, Whereas arm 365, and a central portion of the clutch 367 linked therewith, experiences intermittent limited reciprocating motion under the intermittent action of piston rod 361 and arm 365, such intermittent linear motion is translated by central portion 367, in the known manner of a conventional overrunning clutch, to circular portion 366 thereof and, thus, through pin 368 and shaft 369 to knurled roller 350 fixedly secured to shaft 369 so that an intermittent rotary motion of an extent pro-determined by the setting of adjustable linkage 362 is imparted to knurled roller 350 whereby a predetermined length of abrasive strips 6tia-69a is fed through the machine into Waste strip receptacle 353 for each operation of hydraulic cylinder 360 and each up- 13 ward stroke of arm 365 on overrunning clutch 365-367 attached to knurled roller 35th Because of such automatic feeding of abrasive strips or tapes Gila-69a after each lapping operation, the feeding of such strips or tapes from the rolls 340 thereof through the machine and through knurled feeding rollers 350 and 351 may provide a certain tautness in the tapes or strips being fed. Because, as noted above, certain of the lapping arms must undergo a substantial lateral and vertical reciprocating movement according to the movement of the eccentric crank pins, slack may be desired in at least those of the abrasive strips or tapes being fed through the machine which are engaged with the reciprocating crank pin lapping arms. To provide such necessary slack, notwithstanding the positive and intermitten feeding of additional tape by knurled roll 3513 and 351, there is an arrangement (indicated particularly in FIGS. 2 and whereby a certain slack is taken in the several abrasive strips or tapes between lapping cycles and released during the lapping operation.

Thus, two arms 370* on either side of the machine, are provided on a transverse rotatably mountable shaft 371 for rotation therewith. Between the ends of arms 370 is mounted a rod 372, which rod overlies all the abrasive tapes 6tla-69a in such manner that, upon rotation of rod 371 in FIGS. 2 and 10 in a clockwise direction, rod 372 will depress all the tapes 6911-6911 (as indicated in FIG. 2) to provide a substantial amount of slack therein during the period while knurled rolls 350 and 351 are feeding tape through the machine. Upon rotation of rod 371 in a counter-clockwise direction, however, arms 37% and rod 372 are raised into the position shown in FIG. 10, for relaxation of the slack obtained in order to permit free movement of the moving lapping arms during the lapping operation without straining or breaking any one of the abrasive tapes or strips Gila-63a.

Whereas the actuation and timing of this particular operation with respect to the movements and sequence of movements elsewhere in the machine will become more apparent from the consideration below of FIG. 14, it will be understood here that the particular movements involved are achieved satisfactorily by a linkage associated with the movement of transverse rod 329 under the action of hydraulic cylinder 3257 Thus, bell crank 327, operated by cylinder 325, as previously explained, for the rotation of shaft 320 also has an other arm 375 attached by a link 376 to an arm 377 afiixed to transverse shaft 371 for rotation thereof. Thus, when the piston of cylinder 325 is moved to the right in FIG. 2, it operates bell crank 327-375 so as to rotate shaft 371, through the linkage 375, 376, 377, and, thus, to move arms 370 and transverse rod 372 downwardly (into the position of FIG. 2) to depress or take up slack on the upper portion of abrasive strips title-69a; and, upon the corresponding movement of the piston in cylinder 325 in the opposite direction to the left, rod 371 is similary rotated, through linkage 375-377, to raise arms 370 and rod 372 and release the slack previously obtained in strips la-69a to accommodate the vertical and horizontal reciprocating movement of those of the lapping arms 60-69 which are so moving.

It is desired, also, particularly for automatic operation, to have rotation of the crankshaft 4% between headstock assembly 30 and footstock assembly 35 stopped, at the completion of a lapping cycle, at a particular angular positioning (as adjusted or sensed by the ZLS assembly mounted on housing 11% of headstock assembly 39) in order that the various reciprocating and oscillating lapping arms 62, 64, 66, and 68 may be arrested in the particular vertical and transverse positioning to accommodate, sub stantially without movement, a subsequent crankshaft to be engaged therewith. To this end, an electric braking mechanism and an inching auxiliary drive is provided, as indicated in FIG. 8, to take care of the situation where, after a completed lapping cycle, the crankshaft 40 may 14 not stop in exactly the angular positioning desired. Thus, after the completion of a lapping operation, an electric braking action is applied, preferably, to stop main drive motor 9% promptly after cutting off the current. thereto, and a satisfactory arrangement for accomplishing this is in dicated in FIG. 8.

As illustrated therein, such arrangement comprises a braking mechanism including braking elements 380, pivoted at 381 and urged together by a spring arrangement 382 to exert a clamping or braking action on a braking surface 333 attached to motor drive shaft 91. During non-braking operation, braking elements 38% are held apart by the action of a solenoid S5 through a linkage 384, etc., in known manner. Upon interrupting the electric circuit to main drive motor 90, deenergization of solenoid S5 allows braking elements 389 to close in braking engagement with braking surface 383 on shaft 91 under the action of spring arrangement 332 to stop me rotation of crankshaft 40 by headstock assembly 30 very promptly. If the particular angular positioning of crankshaft 443, as sensed by the 21.5 assembly of FIG. 13, is not precisely as desired, a control circuit, later to be described in connection with FIG. 14, causes solenoid S5 to release the braking action of braking elements 380 and also energizes auxiliary inching motor 390, which acts through a speed reduction gearing indicated at 391 to drive pulley 392 and motor shaft 91 through a belt drive 393 to provide slow or inching movement of the main drive (e.g., through main drive belt 33) of crankshaft 44} to the particularly desired angular positioning thereof as sensed by the 2LS assembly previously described, at which time the current is interrupted to both main drive motor 96* and auxiliary drive motor 390 and the electric braking action of braking elements 380 is allowed, by the deenergization of solenoid S5, to be effective on the main drive shaft 91 under the action of spring 332 to stop rotation of the headstock assembly 30 and crankshaft 46 therein at the particular angular position of rotation desired. Also, preferably, pulley 392 includes an overrunning clutch so that motor 3% stays idle while main motor 90* is running.

Having now described various of the structural elements of a machine embodying and for practising this invention, attention is directed to FIG. 14 as illustrating a schematic or diagrammatic layout of the various mechanical, electrical, and hydraulic control and adjusting elements effecting or performing or controlling the principal and ancillary operations according to this invention, and as diagramrning schematically satisfactory control circuits for the operation of the illustrated embodiment of this invention and/or the particular automatic sequence oi steps and mode of operation thereof.

For simplicity of explanation, the situation of the control circuits of FIG. 14 is shown as, essentially, that of the illustrated embodiment of the machine in the idle position of FIG. 1 between lapping cycles, and, accordingly, with a crankshaft 40 having been loaded into the machine (manually or automatically as from a conveyor indicated by in FIG. 2) and resting on V-blocks 265 and 266 prior to any movement or other action of the machine with regard to crankshaft 40. As so resting and properly oriented (manually or automatically) to present the crankshaft in the desired angular positioning of the eccentric crank pins thereof, one crank pin (e.g., indicated at 404) in FIG. 1) is oriented to depress and close the normally open contacts of a limit switch 3L8 positioned on a bracket 401 adjacent to locating block 402. and attached to bracket 401 by suitable attachment means such as bolts (not shown).

The control arrangements and circuits are preferably designed so that the machine will not operate: without a crankshaft 40 in position, and limit switch 3L5 serves the function of signalling operability to the other control circuits, as well as serving the function of assuring that the particular crankshaft 40 is arranged or indexed into the desired angular position in engagement with locating t F block 462 for accommodation of the automatic sequential subsequent operations. At this moment, the braking elements 384), under the braking action of spring 382, hold the main drive components of the machine stationary and, as noted above with regard to the explanation of the limit switch assembly 2LS, also hold the drive components of headstock assembly 30 in a pre-determined position whereby, with crank pin 4% positioned on limit switch 3L8, drive shaft ltltl of headstock assembly 30 is in such an angular position that drive pin 1M thereof is angularly oriented to engage depression 115 in flange 113 of crankshaft til upon clamping and movement of crankshaft 40 to the left in FIG. 1, as, for example, by movement of footstock assembly center pin 280 to the left under the camming action discussed in connection with FIG. 4.

As noted, the various hydraulic valves and electrical switches and relays diagrammed in H6. 14 are shown in the position thereof with the machine at rest, between cycles, and with the crankshaft 4G in place preparatory to commence operation of a cycle. Thus, hydraulic pump 450 supplies, when operating, hydraulic fluid from a reservoir 451 to operate the various pistons and controls, and is preferably equipped with relief valve 452 for by-passing back to reservoir 451 hydraulic fluid should a predetermined maximum pressure in the hydraulic systern be exceeded.

The system also includes a time delay hydraulic valve 455 normally spring biased to closed position; hydraulically actuated shuttle valve 456; and solenoid operated hydraulic valves 457 and 458, operated, respectively, by solenoids S1 and S2, and both being spring biased to the position shown when the solenoids are deenergized. It is these valving elements which control the timing and sequence of flow of hydraulic fluid from reservoir 4511 under the action of pump 450 to the several previously noted hydraulic cylinder-and-piston motors (e.g., the various cylinders 281 for operating the various jaws 70-79, cylinder 250 for rotating shaft 50, cylinder 325 for rotating transverse shaft 320" for adjustable stops 322 and for the slack-producing arms 370, and cylinder 366 for operating knurled tape feeding roll 350). It should be noted that, for clarity, only one of the lapping arms (in this case 69) has been illustrated in FIG. 14, although a plurality of lapping arm piston-cylinder arrangements 28l 282 are shown as having the hydraulic lines 283 from each cylinder connected to a common manifold 459 and the inlets 284 at the other side of the pistons 282 connected to a common manifold 460, it being understood that, because of the substantial and continuous movement in operation of the cylinder-containing ends of the various lapping arms, it is preferred to have manifolds 45:9 and 460 positioned conveniently on base 25 with the individual lines 283 and 284 to each of the lapping arms being provided in the form of flexible tubing.

With the machine at rest and pump 450 not running (as shown in FIG. 14) valve 455 is spring biased to the right in the drawing to a position which cuts off return flow of hydraulic fluid from hydraulic cylinder 250, thus preventing piston 251 from moving toward the right in the drawing and holding frames 45 and 46 with theheadstock and footstock assemblies thereon to the left hand or loading position. Similarly, the various pistons 282 and the various lapping arms 281 are held to the right to maintain lapping jaws 7tl79 open, the piston in cylinder 325 is held to the right to maintain adjustable stops 322 in operative supporting position, and the piston and cylinder 36% is maintained in the upward position thereof. Also, in this position, limit switch 5LS, mounted adjacent one of the outside lapping arms 69 and operated by a finger or pin 461 on the sliding piston link 286 in thelapping arm, is held open, which pin 461 also operates limit switch 6L8 when the central piston-connected link in lapping arm 69 is moved to the left of the drawing for closing lapping jaw 79 (see also FIG. 11). Also in this aspect of the machine at idle as shown in FIG. 14-, the contacts 176 and 171 of limit switch 2L8 are closed since, as discussed, rotation stops at the particular angular positioning desired as sensed by 2LS.

For operation of the illustrated machine according to the layout of FIG. 14, SW 1 is closed to supply power to the various machine and control circuits, such power coming from main power lines designated as L1 and L2, thus energizing normally closed relay 4CR (through the closed contacts of 2L8) and readying the machine circuits for operation. Closing of SW2 starts hydraulic fluid pump 450 to supply hydraulic fluid under pressure for the various control and machine elements. It is to be understood that the closing of SW1 and SW2 for commencement of operation of the machine or a cycle thereof is not to be considered necessarily a manual operation in connection with this invention because, as is well understood, the initial operation of switches SW1 and SW2 may be actuated by merely the placement of a crankshaft 46 into position on V-blocks 265 and 266, generally, in the same way as the operation limit switch 3L8 is actuated by a crank pin 4% of crankshaft 40.

Hydraulic fluid supplied by pump 459 from reservoir 451 is forced to time delay valve 455 through line 465, and also, through lines 466, 467, 468, etc., to (and through when the valves are open) valve 457, 458, 456, etc. The configuration of the valving piston of time delay valve 455 is arranged to provide a momentary time delay between application of fluid pressure through line 465 and opening of the valve, and this time delay is fur ther controlled by the throttling of hydraulic fluid in line 465 by a needle valve 476, in order to assure full hydraulic pressure at the left side of pistons 282 in lapping arm cylinders 231 to maintain lapping jaws 76-79 open and to assure full hydraulic pressure at the left side of the piston in cylinder 325 to assure adjustable stops for the several lapping jaws in operative position, prior to opening of time delay valve 455 to permit flow communication between hydraulic fluid from cylinder 254) at the right side of piston 251 through valve 455 with either line 467 leading from pump 45%) or line 471 discharging back to reservoir 451 under the selective action of solenoid controlled valve 457. Similarly pressure fluid from lines 466 and 46% passes through solenoid valve 458 and, via line 472, holds shuttle valve 456 in the right hand position thereby permitting pressure fluid to pass therethrough from line 466 to line 473 to hold the piston in cylinder 325 in the right hand position thereof.

Particularly for automatic operation and an automatically timed lapping cycle, an adjustable timer indi' cated within the dotted enclosure T1 is provided to control the duration of the lapping action or cycle, and is shown as having contacts LCl, CO1, and RC1, of which contacts LCl and CCl are closed during a timing cycle and when timer Tl resets, and open at time out of the timing cycle, while contacts RC1 are open during re-set and time out periods, but are closed during timing period. The timing mechanism of timer T1 is conventional and well understood and need not be further spe cifically set forth in detail.

To commence a lapping cycle, with a crankshaft 40 loaded into the machine on V-blocks 265 and 266 and a crank pin dill thereof actuating limit switch 3L8 so that its normally open contacts are closed and its normally closed contacts are open, push button P131 is closed-- either manually or, as above noted, automatically as actuated in known manner from the loading of crankshaft ltl, the loading conveyor, or otherwise. Closing PBll energizes the coil of relays 5CR and ZCR through the now closed, normally open contacts of limit switch 3L8 and closed contacts LCl of timer T1. Upon energization, the normally open contacts of 50R and 2CR close, energizing solenoid S1 in valve 457 and also setting up a holding circuit to maintain the coils of relay 2CR and solenoid S1 energized. Upon energization of solenoid S1, valve 457 is shifted to the right in the drawing against the spring biased action thereof admitting hydraulic fluid from line 467 through line 475 into cylinder 250 at the left side of piston 251, thus rotating shaft 50, through the linkage 252-254, clockwise and swinging frames 45 and 46 and headstock assembly 30 and footstock assembly 35 inwardly to the right in the drawing bringing crankshaft 40 clamped therebetween into lapping or operating position. As previously noted, particularly in the discussion of FIG. 4, such swinging of frames 45 and 46 into operating position brings into play the various cam-actuated means previously discussed for clamping crankshaft 40 and engaging it for rotation with headstock 30, etc., with supporting V-block 265 being moved out of contact with crankshaft 40, etc. During this movement of crankshaft 4% from the loading position to the lapping position, of course, crank pin 400 thereof is moved out of contact with locating block 402 and limit switch 3L8, thus opening the normally open and closing the normally closed contacts thereof.

The closing of the normally open contacts of CR and ZCR also results in energizing the clutch coil TCH of timer T1 to close contacts RC1 of timer T1.

When piston 251 in cylinder 250 has rotated shaft 50 so that the headstock and footstock assembly bring crankshaft 40 into lapping position (i.e., with studs 256 and 257 on frames 45 and 46 resting against stops 258 and 259), frame 45 is in a position to actuate arm 476 of limit switch 4L5, closing the contacts thereof to energize relay 30R through the closed contacts of ZCR, CCl, and SCR. Energization of the coil of relay 3CR closes the contacts thereof to energize solenoid S2 in valve 458, thereby causing shifting of the piston in valve 458 to the right against the spring bias thereof allowing fluid pressure from line 468 to flow into line 476 and, thence, through lines 477 and 478, etc., to move the piston in cylinder 360 downwardly to prepare for rotating tape feed roll 350), to move shuttle valve 456 to the left in the drawing, and to supply hydraulic fluid under pressure to manifold 459 communicating through the several flexible tubes 283 with the right hand end of the several lapping arm cylinders 281. The eifect of this latter flow is to cause all of the lapping arm pistons 282 to move to the left of the drawing, thereby closing the respective lapping jaws 70-79 around the respective main bearing and crank pin portions of crankshaft 40 to be lapped. Preferably a needle valve or throttle valve 480 is interposed in line 477 upstream of manifold 459 to delay or control the rate of closing of jaws 7079 under the action of the leftward movement of pistons 282 in the respective lapping arm cylinders 281. Similarly, a needle throttle valve 481 is provided in the branch of line 472 leading from the left end of shuttle valve 456 for controlling the rate of movement of the piston in shuttle valve 456 to the left (i.e., by controlling the rate of flow of hydraulic fluid out of the cylinder at the left end of shuttle valve 456 and back through line 472 to be re turned to reservoir 451 through valve 458 and return line 482 therefrom.

Movement of shuttle valve 456 to the left in the drawing, accordingly, admits pressure fluid from line 466 through line 484 into the right hand end of cylinder 325, thus urging the piston therein to the left in the drawing, and permits release of pressure fluid at the left end of cylinder 325 back through shuttle valve 456 to discharge line 483, thus releasing the slack imposed by arm 370 on the various abrasive tapes Gila-69a, and moving adjustable stops 322 away from supporting position under crank pin lapping arms 62, 64, 66, and 68. To achieve the desired sequential operation of the various steps, needle valve 481, controlling the discharge of pressure fluid from the left end of shuttle valve 456, is set at a slower rate of flow than is needle valve 480, controlling the flow of pressure fluid to manifold 459 for causing closing of the various lapping jaws 70-79, whereby complete closure and clamping of lapping jaws 70-79 is assured momentarily prior to release of adjustable stops 322 from supporting the several clamping arms and release of slack on the abrasive tapes, and certainly to assure complete clamping of lapping jaws 70-79 prior to the time when rotation of crankshaft 40 begins.

Upon complete closing of lapping jaws 7079 under the action of pistons 282 moving completely to the left of cylinders 281, finger 461 on the sliding link of lapping arm 69 releases normally closed limit switch 5LS, permitting closing thereof, and, a predetermined time later, closes normally open limit switch 6L8, which readies the lapping and rotating circuit, by which time shuttle valve 456 has moved completely to the left to rotate lapping arm adjustable supports 322 out of operative or supporting position and to raise arm 370 so that there is suflicient loose slack in the abrasive tapes to accommodate the eccentric or reciprocating motion of those of the lapping arms which engage eccentric crank pins on crankshaft 40. A further normally open limit switch 'ILS is closed, as by contact with arm 327 of the bell crank operated by cylinder 325, which limit switch, being in series with 6L5, indicates with the latter that all is in readiness for rotation of the crankshaft 40 and that all of the various parts which would interfere with such rotation have been moved out of the way.

With both lLS and 6LS closed, relays 2M and ITR are energized (the latter through the now closed contacts RC1 and SCR). Relay 2M controls the main power switch to motor 90, and relay lTR, being a time delay relay, has a set of normally closed contacts which are delayed from closing when 1TR is deenergized and another set of normally open contacts which break or make immediately upon energization or deenergization of lTR, respectively. Thus, upon energization of the coil of relay lTR, upon closing of 1LS and 6LS, the normally open contacts thereof close and the time delayed normally closed contacts thereof open immediately. The closed contacts of HR maintain the energization of the coil of relay 4CR to prevent intermittent opening and closing thereof as limit switch ZLS is repeatedly opened and closed (once with each repeated revolution of rotor during rotation of drive shaft 106 of headstock assembly 30. As noted, energization of the coil of relay 2M closes all of the normally open contacts thereof, thus energizing drive motor 94 and also energizing solenoid S5 causing release of braking elements 380 engaging brake drum 383 on motor shaft 91. At the same time as drive motor 90 is started, the motor M of timer T1 is started, and it is this timer motor M which governs the number of revolutions and duration of each individual lapping cycle. Hence, crankshaft 40 is rotated between headstock 30 and footstock 35 for the duration of the timing cycle, as determined by timer motor M, at the end of which timer T1 times out and rotation ceases.

When timer T1 times out, after a predetermined time interval and/or a predetermined number of revolutions of crankshaft 40, contacts LC1, CCl, and RC1 in timer T1 open. Opening of contacts RC1, of course, deenergizes the coils of relays 2M and HR, which action opens the contacts of relay 2M effecting cutting off power to main drive motor 90 and to timer motor M of timer T1, and also deenergizes solenoid S5, thus releasing braking elements 380 for braking action against motor shaft 91 under the urging of spring arrangement 382.. At the same time, the normally open contacts of time delay relay ITR open immediately, thus deenergizing relay 4CR-provided that rotation of crankshaft 40 has not stopped or crankshaft 40 has not been braked to a stop at the particular angular position where contacts and 171 of limit switch 2LS are allowed to close by rubbing block engaging flat 172 on rotor 165 of the rotation sensing mechanism of 2LS. The normally closed contacts of relay 4CR close, one set of these contacts maintaining the coil of relay SCR and solenoid S2 energized, because contacts CO1 in the timer are now open.

When relay 4CR is deenergized as described above, the other set of normally closed contacts of 4CR relays power from the time delay relay ITR contacts, which will close shortly after deenergization of the coil of IT R, thus energizing relay 3M to close normally open contacts thereof to energize auxiliary drive motor 3%, and again energize solenoid S to release braking members 380, and to start auxiliary drive or positioning or inching motor 390, operating through a speed reduction gear 391, to rotate shaft 100' of headstock assembly and crankshaft 40 slowly until limit switch ZLS can close, reenergizing relay 4CR, which deenergizes relay 3M and 3CR, once again stopping auxiliary motor 3% and deenergizing solenoid S5 to allow brake members 389 to stop motor shaft 91 again under the action of spring arrangement 382. Crankshaft 40 and drive pin 114 on headstock assembly 34) have now stopped in the correct angular positioning for arranging the oscillating and reciprocating lapping arms 62, 64, 66, and 68, and the appertaining and/or associated elements of the device for release of finished crankshaft 40 and in a position to receive, Without readjustment, a subsequent crankshaft to be lapped or polished and presented to the machine in the same angular position.

If the crankshaft 40 should stop in the correct angular position for loading the next crankshaft, contacts 170 and 171 of limit switch 2L8 will be closed because rubbing block 175 will be in engagement with flat 172 on rotor 165. With contacts I176 and 171 closed relay 40R remain-s energized, holding its contacts open so that the subsequent closing of the time delayed contacts of time delay relay ITR will not result in energizing relay 3M to actuate the auxiliary drive motor 390.

Deenergization of the coil of relay SCR deenergizes solenoid S2 and allows valve 458 to move to the left under the action of the biasing spring therein. Such movement, returning valve 453 to the position illustrated in FIG. 14, passes hydraulic fluid to move shuttle valve 456 back to the right in the drawing, and also passes hydraulic fluid to the left end of piston 325 to move lapping arm adjustable support 322 counter-clockwise in the drawing and back into supporting position, along with moving arms 370 into slack-producing position and feeding an additional length of abrasive tapes through the machine under the action of cylinder 36%} acting upon clutch arm 365 on knurled feeding roller The counter-clockwise rotation of bellcrank 327 in response to this displacement of piston 325 also opens limit switch ltLS. At the same time, hydraulic fluid under pressure enters the left end of the several lapping arm cylinders 281 (as fed from manifold 460 into the various flexible conduits 284) urging the pistons 2 82 to the right, the timing of this sequence of motions if partially controlled by needle valve 480 regulating the rate of discharge flow of fluid out of manifold 459, since the flow through needle valve .8% is less than that through a one-way check valve 491 leading to the left end of valve 456.

As the piston connecting rods in the lapping arms move to the right in the drawing, finger 461 on lapping arm 69 permits opening of the limit switch 6LS and, a moment later, opens the normally closed contacts of limit switch 5L8, thus deenergizing relay 20R (which was being held in the circuit by 5L8 after contacts LC} of timer T1 opened when the timer timed out). Deenergization of relay ZCR then deenergizes the clutch coil of timer T1, which timer re-sets automatically, and also deenergizes relay SCR and solenoid S1. The contacts of ECR open and the contacts LC and DC]. of timer T1 close, while the contacts RC1 of the timer remain open. Deenergization of solenoid S1 allows valve 457 to move to the left in the drawing under the spring :biasecl action thereof, allowing pressure fluid to pass through valve 455 (now held to the left) and into the right end of cylinder 25% to move piston 251 therein and rotate shaft 50 countor-clockwise, thus swinging frames 45 and 46 (and the headstock and footstock mounted thereon and crankshaft 40 clamped therebetween) to the left into unloading position. Preferably needle valves 4-93 and 494 are interposed into the hydraulic lines leading into: cylinder 250 to cushion the action thereof at the extreme end positions of the stroke.

During this swinging movement, limit switch 4L5 is opened, as by frame 45 moving out of contact therewith to the left in the drawing, and the spindle 200 of footstock assembly 35 is retracted by the cam-actuated action discussed in connection with FIG. 4, which action also retracts rod 231, pulling crankshaft 40 away from headstock assembly 30 and disengaging drive pin 114 from flange 113 in crankshaft 4t). Concurrently, V-block 265 is raised into supporting position and crankshaft 40 drops from engagement between headstock assembly 30 and footstock assembly 35 to rest on V-blocks 265 and 266 to await manual or automatic removal. It should be noted that limit switch 3L8 is actuated, as at the start of the cycle, by crank pin 4% of crankshaft 40, but this actuation has no effect on the machine at this time since switch PBi has not been reactivated to recommence a cycle.

Thus, the finished crankshaft 4t) is manually or automatically removed and replaced with a subsequent crankshaft in the same angular positioning (which is, in large measure, determined by rotation of the crankshaft in V blocks 265 and 266 under the force of gravity as a selected crank pin 400 thereof not only contacts but is supported by locating block 402). With a new crankshaft in place, closing switch PBl reactivates the complete cycle.

it should also be noted that a normally closed push button P132 is included, preferably, so that opening of this switch will stop the cycle at any point thereof as may be desired. Also indicated in FIG. 14 is a selector switch arrangement SS1 for selection between manual and automatic operation. As shown in the drawing, the SS1 circuit is arranged for automatic operation, but with the SS1 contacts open or in the manual setting, switches SW3 and SW4 are manually operated to perform and control the lapping cycle disclosed.

It is also desired that the feeding of new lengths of abrasive tapes 6tla69a occur after the finished crankshaft is completely removed from lapping jaws 7t)-79, for example, to avoid possible scratching of the newly polished surface by feeding abrasive tape. To this end needle valve 490, controlling exhaust of hydraulic fluid from the upper end of cylinder 360, is set for a very slow rate of flow so that the upward stroke of cylinder 369 is not completed for actuation of a feeding motion of arm 365 until there has been ample opportunity for the polished portions of crankshaft 4G to be moved completely out of lapping jaws '7tl79. Also, such feeding of new lengths of abrasive strips or tapes may produce tautness of the tape over the open lapping jaws 7979. Since a positive clamping of tape a6a is produced by the interaction of knurled rolls 350 and 351, any such tautness is eliminated as a new crankshaft is moved into the lapping jaws by having the horizontal movement of the crankshaft withdraw more tape from the freely rotating tape supply rolls 34d. For completeness, it may be desired to provide a coolant flow over the surfaces being lapped or polished, and provision in the illustrated machine for such flow is made by nozzles 495 supplied with coolant through a manifold 49,6 and pipe 497 from coolant tank 498 by pump 499.

While the forms of apparatus herein described constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

I claim:

1. In a lapping machine of the character described for finishing simultaneously different predetermined portions of a workpiece by rotation and reciprocation thereof against an abrasive medium held against the portions being finished the combination which comprises headstock and footstock means for clamping a workpiece therebetween, main drive means in said machine for rotating a workpiece when clamped between said headstock and footstock means, a plurality of lapping jaws for holding said abrasive medium against predetermined portions of a workpiece to be finished, lapping arm means mounted in said machine for supporting said lapping jaws individually positioned for engaging the portions of a workpiece to be finished, means for swinging said headstock and footstock means from an outward loading position for receiving a workpiece and spaced from said lapping jaws to an inward lapping position for engagement of a workpiece by said lapping jaws, and means automatically operable as said headstock and footstock means are swung from the outward loading position to the inward lapping position to clamp a workpiece between said headstock and footstock means.

2. In a lapping machine of the character described for lapping simultaneously different predetermined portions of a workpiece by rotation and reciprocation of a workpiece against an abrasive medium held against the portions being lapped, the combination which comprises headstock and footstock means for clamping a workpiece therebetween, drive means in said machine including means for rotating and axially reciprocating a workpiece when clamped between said headstock and footstock means, a plurality of lapping jaws for holding said abrasive medium against the portions of a workpiece to be lapped, lapping ar-m means mounted in said machine for supporting said lapping jaws individually positioned for engaging the portions of a workpiece to be lapped, means for swinging said headstock and footstock means from an outward loading position with the headstock and footstock means unclamped for receiving a workpiece and spaced from said lapping jaws to an inward lapping position with a workpiece clamped between said headstock and footstock means for engagement of a workpiece by said lapping jaws, and means automatically operable as said headstock and footstock means are swung from the outward loading position to the inward lapping position to advance said footstock means to clamp a workpiece and automatically operable as said headstock and footstock means are swung from the inward lapping position to the outward loading position to retract said footstock means to release a lapped workpiece and to receive a workpiece to be lapped between said headstock and footstock means.

3. In a lapping machine of the character described for lapping simultaneously different predetermined portions of a workpiece by rotation and reciprocation of a workpiece against a flexible abrasive material held wrap ped around the portions being lapped, the combination which comprises coaxially disposed headstock and footstock means for clamping a workpiece therebetween, pivotally mounted supporting means for said headstock and footstock means, drive means in said machine including means for rotating a workpiece when clamped between said headstock and footstock means, a plurality of lapping jaws for holding said abrasive material wrapped around predetermined portions of a workpiece to be lapped, lapping arm means mounted in said machine for supporting said lapping jaws individually in different positions for engaging different ones of predetermined portions of a workpiece to be lapped, means for swinging said supporting means and thence said headstock and footstock means from an outward loading position for receiving a workpiece and spaced from said lapping jaws to an inward lapping position for engagement of a workpiece by said lapping jaws, and means for producing coordinated reciprocation of said headstock and footstock means relative to said supporting means and along their common axis during rotation of a workpiece and while predetermined portions thereof to be lapped are engaged by said lapping jaws.

4. In an automatic crankshaft lapping machine of the character described for lapping simultaneously a plurality of concentric portions and a plurality of eccentric portions of a crankshaft by rotation of a crankshaft about its axis of rotation while the various portions to be lapped are separately engaged by an abrasive medium, the com bination which comprises headstock and footstock means for clamp-ing said crankshaft therebetween, drive means for rotating a crankshaft about its axis of rotation, a plurality of separate lapping jaws for individually engaging the various concentric and eccentric portions of a crankshaft and for holding said abrasive medium thereagainst for the lapping thereof during rotation of said shaft, means for mounting said lapping jaws in said machine for different pivoting and reciprocating movements to follow the various movements of the different concen tric and eccentric portions of a crankshaft during rotation thereof, means for swinging said headstock and footstock means from an outward loading position spaced from said lapping jaws to an inward lapping position at which the various portions of a crankshaft are individually engaged by said lapping jaws, temporary supporting means for supporting a crankshaft between said headstock and footstock means prior to the clamping of a crankshaft therebetween, and means automatically operable as said headstock and footstock means are swung from the outward loading position to the inward lapping position to clamp a crankshaft between said headstock and footstock means.

5. In an automatic crankshaft lapping machine of the character described for lapping simultaneously a plurality of concentric portions and a plurality of eccentric portions of a crankshaft by rotation of a crankshaft about its axis of rotation while the various portions to be polished are separately engaged by an abrasive medium, the combination which comprises headstock and footstock means for clamping a crankshaft therebetween at the ends thereof, drive means for rotating a crankshaft about its axis of rotation, a plurality of separate lapping jaws for individually engaging the various concentric and eccentric portions of a crankshaft and for holding said abrasive medium thereagainst for the lapping thereof during rotation of a crankshaft, lapping arm means for supporting said lapping jaws, means for mounting said lapping arm means in said machine for different pivoting and reciprocating movements of said jaws to follow the various movements of the different concentric and eccentric portions of a crankshaft during rotation thereof, means for swinging said headstock and footstock means from an outward loading position spaced from said lapping jaws to an inward lapping position at which the various portions of a crankshaft are individually engaged by said lapping jaws, and menas coacting with said headstock and footstock means for automatically clamping and locking a crankshaft therebetween for rotation, said last mentioned means being automatically actuated during the swinging movement of said headstock and footstock means from said outer loading position to said inner lapping position.

6. In an automatic crankshaft lapping machine of the character described for lapping simultaneously a plurality of concentric portions and a plurality of eccentric portions of a crankshaft by rotation of a crankshaft about its axis of rotation while the various portions to be lapped are separately engaged by an abrasive medium, the combination which comprises a supporting frame mounted for pivotal movement about a fixed axis, headstock and footstock means for clamping a crankshaft therebetween at the ends thereof, said headstock and footstock means being slidably mounted upon said supporting frame, drive means effective through said headstock means for rotating a crankshaft about its axis of rotation and for reciprocating a crankshaft axially, a plurality of separate lapping jaws for individually engaging the various concentric and eccentric portions of a crankshaft and for holding said abrasive medium thereagainst for the lapping thereof durihg the rotation of a crankshaft, indi vidual lapping arms for supporting said lapping jaws, means for individually mounting said lapping arms in said machine for different pivoting and reciprocating movement thereof to follow the variou movements of the different concentric and eccentric portions of a crankshaft during rotation thereof, means for swinging said supporting frame and thence said headstock. and footstock means from an outward loading position spaced from said lapping jaws to an inward lapping position at which the various portions of a crankshaft are individually engaged by said lapping jaws, means coacting with said headstock and footstock means automatically operable as said headstock and footstock means are swung from the outward loading position to the inward lapping position to clamp and look a crankshaft therebetween for rotation about its axis and reciprocation with said headstock and footstock means, means automatically operable when said headstock and footstock means are disposed in the inward lapping position to produce coordinated reciprocation of said headstock and footstock means relative to said supporting frame, and temporary supporting means for supporting a crankshaft between said headstock and footstock means prior to clamping of a crankshaft therebetween.

7. In an automatic control system for actuating and controlling automatically the sequence of separate operations and movements of a crankshaft lapping machine of the character described having a plurality of pivotally mounted lapping arms with closable lapping jaws for holding strips of abrasive tape separately against various concentric main bearing portions and eccentric crankpin portions of a crankshaft and having headstock and footstock means for clamping and rotating and reciprocating a crankshaft therebetween and being swingable from a first fixed outward loading position to a second fixed inward lapping position for engagement of the concentric and eccentric portions of a crankshaft individually by said lapping jaws, the combination which comprises hydraulically operated means for swinging said headstock and footstock selectively in either direction between said first and second fixed positions thereof and for selectively opening and closing said lapping jaws in timed relation to said swinging movement, drive means for rotating and reciprocating a crankshaft, automatic control means for actuating'said hydraulically operated means and for selecting the sequence and direction of said swinging and opening and closing movements effected thereby, said control means including means for energizing said drive means and timer means for stopping said drive means after a predetermined cycle, and means automatically operable to reset said control means and said machine at the end of each lapping cycle to repeat the cycle upon removal of a finished crankshaft from the machine and loading of a new crankshaft thereinto.

8. In an automatic control system for actuating and controlling automatically the sequence of separate operations and movements of a crankshaft lapping machine of the character described having a plurality of pivotally mounted lapping arms with closable lapping jaws for holding strips of abrasive tape separately against various concentric main bearing portions and eccentric crankpin portions of a crankshaft and having headstock and footstock means for clamping and rotating and reciprocating a crankshaft therebetween and being swingable from a first fixed outward loading position to a second fixed inward lapping position for engagement of the concentric and eccentric portions of a crankshaft individually by said lapping jaws, the combination which comprises hydraulically operated means for swinging said headstock and footstock selectively in either direction between said first and second fixed positions thereof and for selectively opening and closing said lapping jaws in timed relation to said swinging movement, drive means for rotating and reciprocating a crankshaft, automatic control means for actuating said hydraulically operated means and for selecting the sequence and direction of said swinging and opening and closing movements effected thereby, said control means including means for energizing said drive means and timer means for stopping said drive means after a predetermined cycle, automatically actuated means for positively stopping rotation of a crankshaft at a particular predetermined angular position thereof, retractable lapping arm supporting means automatically actuated before said lapping jaws are opened to support said lapping arms in positions determined by the predetermined angular position of a crankshaft clamped between said headstock and footstock means, and means for resetting said control means at the end of each lapping cycle to repeat the cycle upon removal of a finished crankshaft from the machine and loading of a new crankshaft thereinto.

9. In a lapping machine as described in claim 1, the combination with the features recited therein of automatically operable means for positioning a new portion of said abrasive medium in engagement with the portions of a work piece being polished for each succeeding work piece inserted in said lapping and polishing machine.-

lO. The combination of features in a lapping machine as described in claim 1, wherein said lapping arm means includes automatically operable supporting means movable between an extended position in which selected lapping jaws are supported in a proper position to receive a work piece and a retracted position in which said lapping jaws are free to move with the portions of the work piece engaged by the respective lapping jaws.

11. In an automatic crankshaft lapping machine as described in claim 4, said temporary supporting means including at least one movable support mounted for movement into an extended position adjoining a crankshaft When said headstock and footstock means are in an outward loading position and into a retracted position remote from a crankshaft when said headstock and footstock means are in an inward lapping position, and actuating means for moving said support between its extended position and its retracted position.

12. In an automatic control system as described in claim 7, automatically operable supporting means movable into engagement with selected lapping arms at the end of each lapping cycle to properly position said lapping arms for engagement with eccentric crankpin portions of a crankshaft, and movable out of engagement with selected lapping arms at the beginning of each lapping cycle to permit movement of said selected lapping arms with the eccentric portions of a crankshaft.

13. In an automatic control system as described in claim 12, automatically operable feed means actuated during each lapping cycle for displacing said strips of abrasive tape to position successive portions thereof against the various concentric main portions and eccentric crankpin portions of different crankshafts inserted in a crankshaft lapping machine during successive lapping cycles.

14. In an automatic control system as described in claim 8, automatically operable supporting means movable into engagement with selected lapping arms at the end of each lapping cycle to properly position said lapping arms for engagement with eccentric crankpin portions of a crankshaft, and movable out of engagement with selected lapping arms at the beginning of each lapping cycle to permit movement of said selected lapping arms with the eccentric portions of a crankshaft.

15. In an automatic control system as described in claim 14, automatically operable feed means actuated during each lapping cycle for displacing said strips of abrasive tape to position successive portions thereof a against the various concentric main portions and eccentric crankpin portions of diiferent crankshafts inserted in a crankshaft lapping machine during successive lapping cycles.

16. In a machine of the character described for finishing simultaneously dilferent predetermined portions of a workpiece by rotation thereof against an abrasive medium held against the portions being finished, the combination which comprises headstock and footstock means for clamping a workpiece therebetween, said headstock and footstock means being swingable from a first fixed outward loading position to a second fixed inward lapping position, drive means in said machine for rotating a workpiece when clamped between said headstock and footstock means, a plurality of lapping ja-ws for holding said abrasive medium against predetermined portions of a workpiece to be finished, lapping arm means mounted in said machine for supporting said lapping jaws individually positioned for engaging the portions of a workpiece to be finished, and automatically operable means for swinging said headstock and footstock means from said first fixed outward loading position for receiving a workpiece and spaced from said lapping jaws to said second fixed inward lapping position for engagement of a workpiece by said lapping jaws.

17. In a lapping machine as described in claim 1, the combination with the features recited therein of means operable automatically after a work piece is lapped to bring each work piece to rest in the same predetermined angular orientation while said lapping jaws are disposed in engagement with each work piece.

18. The combination of features in a lapping machine as described in claim 17, wherein said lapping arm means includes automatically operable supporting means movable between an extended position in which selected lapping jaws are supported in a proper position to receive a work piece disposed in said predetermined angular orientation and a retracted position in which said lapping jaws are free to move with the portions of the work piece engaged by the respective lapping jaws.

19. In a lapping machine as described in claim 5, the combination with the features recited therein of means operable automatically after a crankshaft is lapped to bring each crankshaft to rest in the same predetermined angular orientation while said lapping jaws are disposed in engagement with each crankshaft.

20. The combination of features in a lapping machine as described in claim- 19, wherein said lapping arm means includes automatically operable supporting means movable between an extended position in which selected lapping jaws are supported in a proper position to receive a. crankshaft disposed in said predetermined angular orientation and a retracted position in which said lapping jaws are free to move with the eccentric portions of the crankshaft engaged by the respective lapping jaws.

References Cited in the file of this patent UNITED STATES PATENTS 2,166,086 Wood July 11, 1939 2,261,902 Indge Nov. 14, 1941 2,503,889 Silven et al Apr. 11, 1950 2,725,689 Dexter Dec. 6, 1955 

